A procedure is described for determining the minimal length of a mastery test given certain constraints. The procedure assumes that the testor is indifferent to misclassifying some testees who score within a specified range about the passing score. An example and table are provided. (JKS)

The formula developed by R. Levine (1955) for equating unequally reliable tests is described. The formula can be interpreted as a method of moments estimate of an equating function that results in first order equity of the equated test score under a classical congeneric model. (TJH)

Issues regarding tolerance and confidence intervals are discussed within the context of educational measurement, and conceptual distinctions are drawn between these two types of intervals. Points are raised about the advantages of tolerance intervals when the focus is on a particular observed score rather than a particular examinee. (Author/BW)

False-positive and false-negative decisions are the two possible errors committed with a mastery test; yet the estimation of the likelihood of committing these errors has not been investigated. Two methods of this type of estimation are presented and discussed. (Author/JKS)

Methods are described for obtaining upper and lower bounds to both false-positive and false-negative decisions with a mastery test. These methods make no assumptions about the form of the true score distribution. (CTM)

For anchor test equating, 3 linear observed score methods are derived for populations differing in ability. Each version requires that the correlations of the tests with the selection variable be known. Five sets of assumptions are made for each model--yielding 15 methods--which are then related to existing methods. (SLD)

A number of models are proposed of the effects of demographic and environmental factors on IQ and its pattern of change over time. The proposed models are concerned with the determinants of an individual's true (but unobserved) IQ and the relationship between measured and true IQ's. (Author/RC)

This commentary focuses on the application of D. Rogosa and G. Ghandour's work to observational research on classroom processes. Rogosa and Ghandour have shown that the short length of an observation is typically the dominant source of error. Investigators should conduct observations for as long as possible. (SLD)

The monograph by D. Rogosa and G. Ghandour represents a body of cohesive and comprehensive research that can be the basis of a new measurement theory combining features of generalizability theory and strong true-score theory. Principles, approaches, arguments, and conclusions are reviewed; and critical comments are offered. (SLD)

Issues raised with the statistical models developed are discussed point by point, restating the emphasis on finite observation time, and reiterating the criticism of traditional psychometric methods. It is noted that the language and technical formulation of psychometrics can be extremely awkward in dealing with biased estimates. (SLD)

Natural statistical models based on renewal processes for individuals' Behavior Stream are developed. For continuous observation, statistical and psychometric properties are obtained for empirical: (1) rates of behavior; (2) proportions of behavior type; (3) prevalence; and (4) event duration. Results provide a guide for design and analysis. (SLD)